Tribological properties of ultrahigh-molecular-weight polyethylene (UHMWPE) composites reinforced with different contents of glass and carbon fibers

Purpose This purpose of this study was to investigate the effects of carbon fiber (CF) and/or glass fiber (GF) fillers on the tribological behaviors of ultrahigh-molecular-weight polyethylene (UHMWPE) composites to develop a high-performance water-lubricated journal bearing material. Design/methodology/approach Tribological tests were conducted using a pin-on-disc tribometer using polished GCr15 steel pins against the UHMWPE composite discs under dry conditions with a contact pressure of 15 MPa and a sliding speed of 0.15 m/s. Scanning electron microscopy, laser 3D micro-imaging profile measurements and energy-dispersive X-ray spectrometry were used to analyze the morphologies and elemental distributions of the worn surfaces. Findings The results showed that hybrid CF and GF fillers effectively improved the wear resistance of the composites. The fiber fillers decreased the contact area, promoted transfer from the polymers and decreased the interlocking and plowing of material pairs, which contributed to the reduction of both the friction coefficient and the wear rate. Originality/value The UHMWPE composite containing 12.5 Wt.% CF and 12.5 Wt.% GF showed the best wear resistance of 2.61 x 10(-5) mm(3)/(N center dot m) and the lower friction coefficient of 0.12 under heavy loading. In addition, the fillers changed the worn surface morphology and the wear mechanism of the composites.